<!DOCTYPE HTML>
<html lang="en" >
    
    <head>
        
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <title>函数 | Swift 简介</title>
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
        <meta name="description" content="">
        <meta name="generator" content="GitBook 2.1.0">
        
        
        <meta name="HandheldFriendly" content="true"/>
        <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
        <meta name="apple-mobile-web-app-capable" content="yes">
        <meta name="apple-mobile-web-app-status-bar-style" content="black">
        <link rel="apple-touch-icon-precomposed" sizes="152x152" href="gitbook/images/apple-touch-icon-precomposed-152.png">
        <link rel="shortcut icon" href="gitbook/images/favicon.ico" type="image/x-icon">
        
    <link rel="stylesheet" href="gitbook/style.css">
    
    

        
    
    
    <link rel="next" href="./09-closure.html" />
    
    
    <link rel="prev" href="./07-collection.html" />
    

        
    </head>
    <body>
        
        
    <div class="book" data-level="0.8" data-basepath="." data-revision="Sun Jul 26 2015 06:31:06 GMT+0800 (CST)">
    

<div class="book-summary">
    <div class="book-search">
        <input type="text" placeholder="Type to search" class="form-control" />
    </div>
    <ul class="summary">
        
        
        
        

        

        
    
        <li class="chapter " data-level="0" data-path="index.html">
            
                
                    <a href="./index.html">
                        <i class="fa fa-check"></i>
                        
                        Swift快速入门
                    </a>
                
            
            
            <ul class="articles">
                
    
        <li class="chapter " data-level="0.1" data-path="01-playground.html">
            
                
                    <a href="./01-playground.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.1.</b>
                        
                        Playground
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.2" data-path="02-var_and_let.html">
            
                
                    <a href="./02-var_and_let.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.2.</b>
                        
                        变量和常量
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.3" data-path="03-optional.html">
            
                
                    <a href="./03-optional.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.3.</b>
                        
                        Optional可选值
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.4" data-path="04-control_flow.html">
            
                
                    <a href="./04-control_flow.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.4.</b>
                        
                        控制流
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.5" data-path="05-loop.html">
            
                
                    <a href="./05-loop.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.5.</b>
                        
                        循环
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.6" data-path="06-string.html">
            
                
                    <a href="./06-string.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.6.</b>
                        
                        字符串
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.7" data-path="07-collection.html">
            
                
                    <a href="./07-collection.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.7.</b>
                        
                        集合
                    </a>
                
            
            
        </li>
    
        <li class="chapter active" data-level="0.8" data-path="08-func.html">
            
                
                    <a href="./08-func.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.8.</b>
                        
                        函数
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.9" data-path="09-closure.html">
            
                
                    <a href="./09-closure.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.9.</b>
                        
                        闭包
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.10" data-path="10-init_func.html">
            
                
                    <a href="./10-init_func.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.10.</b>
                        
                        构造函数
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.11" data-path="11-lazy.html">
            
                
                    <a href="./11-lazy.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.11.</b>
                        
                        懒加载 &amp; didSet
                    </a>
                
            
            
        </li>
    
        <li class="chapter " data-level="0.12" data-path="12-ats.html">
            
                
                    <a href="./12-ats.html">
                        <i class="fa fa-check"></i>
                        
                            <b>0.12.</b>
                        
                        ATS
                    </a>
                
            
            
        </li>
    

            </ul>
            
        </li>
    


        
        <li class="divider"></li>
        <li>
            <a href="https://www.gitbook.com" target="blank" class="gitbook-link">
                Published with GitBook
            </a>
        </li>
        
    </ul>
</div>

    <div class="book-body">
        <div class="body-inner">
            <div class="book-header">
    <!-- Actions Left -->
    <a href="#" class="btn pull-left toggle-summary" aria-label="Table of Contents"><i class="fa fa-align-justify"></i></a>
    <a href="#" class="btn pull-left toggle-search" aria-label="Search"><i class="fa fa-search"></i></a>
    
    <div id="font-settings-wrapper" class="dropdown pull-left">
        <a href="#" class="btn toggle-dropdown" aria-label="Font Settings"><i class="fa fa-font"></i>
        </a>
        <div class="dropdown-menu font-settings">
    <div class="dropdown-caret">
        <span class="caret-outer"></span>
        <span class="caret-inner"></span>
    </div>

    <div class="buttons">
        <button type="button" id="reduce-font-size" class="button size-2">A</button>
        <button type="button" id="enlarge-font-size" class="button size-2">A</button>
    </div>

    <div class="buttons font-family-list">
        <button type="button" data-font="0" class="button">Serif</button>
        <button type="button" data-font="1" class="button">Sans</button>
    </div>

    <div class="buttons color-theme-list">
        <button type="button" id="color-theme-preview-0" class="button size-3" data-theme="0">White</button>
        <button type="button" id="color-theme-preview-1" class="button size-3" data-theme="1">Sepia</button>
        <button type="button" id="color-theme-preview-2" class="button size-3" data-theme="2">Night</button>
    </div>
</div>

    </div>

    <!-- Actions Right -->
    
    <div class="dropdown pull-right">
        <a href="#" class="btn toggle-dropdown" aria-label="Share"><i class="fa fa-share-alt"></i>
        </a>
        <div class="dropdown-menu font-settings dropdown-left">
            <div class="dropdown-caret">
                <span class="caret-outer"></span>
                <span class="caret-inner"></span>
            </div>
            <div class="buttons">
                <button type="button" data-sharing="twitter" class="button">
                    Share on Twitter
                </button>
                <button type="button" data-sharing="google-plus" class="button">
                    Share on Google
                </button>
                <button type="button" data-sharing="facebook" class="button">
                    Share on Facebook
                </button>
                <button type="button" data-sharing="weibo" class="button">
                    Share on Weibo
                </button>
                <button type="button" data-sharing="instapaper" class="button">
                    Share on Instapaper
                </button>
            </div>
        </div>
    </div>
    

    
    <a href="#" target="_blank" class="btn pull-right google-plus-sharing-link sharing-link" data-sharing="google-plus" aria-label="Google"><i class="fa fa-google-plus"></i></a>
    
    
    <a href="#" target="_blank" class="btn pull-right facebook-sharing-link sharing-link" data-sharing="facebook" aria-label="Facebook"><i class="fa fa-facebook"></i></a>
    
    
    <a href="#" target="_blank" class="btn pull-right twitter-sharing-link sharing-link" data-sharing="twitter" aria-label="Twitter"><i class="fa fa-twitter"></i></a>
    
    
    


    <!-- Title -->
    <h1>
        <i class="fa fa-circle-o-notch fa-spin"></i>
        <a href="./" >Swift 简介</a>
    </h1>
</div>

            <div class="page-wrapper" tabindex="-1">
                <div class="page-inner">
                
                
                    <section class="normal" id="section-">
                    
                        <h1 id="%E5%87%BD%E6%95%B0">&#x51FD;&#x6570;</h1>
<ul>
<li>&#x51FD;&#x6570;&#x7684;&#x5B9A;&#x4E49;<ul>
<li>&#x683C;&#x5F0F; <code>func &#x51FD;&#x6570;&#x540D;(&#x884C;&#x53C2;&#x5217;&#x8868;) -&gt; &#x8FD4;&#x56DE;&#x503C; {&#x4EE3;&#x7801;&#x5B9E;&#x73B0;}</code></li>
<li>&#x8C03;&#x7528; <code>let result = &#x51FD;&#x6570;&#x540D;(&#x503C;1, &#x53C2;&#x6570;2: &#x503C;2...)</code></li>
</ul>
</li>
</ul>
<pre><code class="lang-swift"><span class="hljs-func"><span class="hljs-keyword">func</span> <span class="hljs-title">sum</span><span class="hljs-params">(a: Int, b: Int)</span> -&gt; <span class="hljs-title">Int</span> </span>{
    <span class="hljs-keyword">return</span> a + b
}

<span class="hljs-keyword">let</span> result = sum(<span class="hljs-number">10</span>, b: <span class="hljs-number">20</span>)
</code></pre>
<ul>
<li>&#x6CA1;&#x6709;&#x8FD4;&#x56DE;&#x503C;&#x7684;&#x51FD;&#x6570;&#xFF0C;&#x4E00;&#x5171;&#x6709;&#x4E09;&#x79CD;&#x5199;&#x6CD5;<ul>
<li>&#x7701;&#x7565;</li>
<li>()</li>
<li>Void</li>
</ul>
</li>
</ul>
<pre><code class="lang-swift"><span class="hljs-func"><span class="hljs-keyword">func</span> <span class="hljs-title">demo</span><span class="hljs-params">(str: String)</span> -&gt; <span class="hljs-title">Void</span> </span>{
    <span class="hljs-built_in">print</span>(str)
}
<span class="hljs-func"><span class="hljs-keyword">func</span> <span class="hljs-title">demo1</span><span class="hljs-params">(str: String)</span> -&gt; <span class="hljs-params">()</span> </span>{
    <span class="hljs-built_in">print</span>(str)
}
<span class="hljs-func"><span class="hljs-keyword">func</span> <span class="hljs-title">demo2</span><span class="hljs-params">(str: String)</span> </span>{
    <span class="hljs-built_in">print</span>(str)
}

demo(<span class="hljs-string">&quot;hello&quot;</span>)
demo1(<span class="hljs-string">&quot;hello world&quot;</span>)
demo2(<span class="hljs-string">&quot;olleh&quot;</span>)
</code></pre>
<ul>
<li>&#x5916;&#x90E8;&#x53C2;&#x6570;<ul>
<li>&#x5728;&#x5F62;&#x53C2;&#x540D;&#x524D;&#x518D;&#x589E;&#x52A0;&#x4E00;&#x4E2A;&#x5916;&#x90E8;&#x53C2;&#x6570;&#x540D;&#xFF0C;&#x80FD;&#x591F;&#x65B9;&#x4FBF;&#x8C03;&#x7528;&#x4EBA;&#x5458;&#x66F4;&#x597D;&#x5730;&#x7406;&#x89E3;&#x51FD;&#x6570;&#x7684;&#x8BED;&#x4E49;</li>
<li>&#x683C;&#x5F0F;&#xFF1A;<code>func &#x51FD;&#x6570;&#x540D;(&#x5916;&#x90E8;&#x53C2;&#x6570;&#x540D; &#x5F62;&#x5F0F;&#x53C2;&#x6570;&#x540D;: &#x5F62;&#x5F0F;&#x53C2;&#x6570;&#x7C7B;&#x578B;) -&gt; &#x8FD4;&#x56DE;&#x503C;&#x7C7B;&#x578B;  { // &#x4EE3;&#x7801;&#x5B9E;&#x73B0; }</code></li>
<li>Swift 2.0 &#x4E2D;&#xFF0C;&#x9ED8;&#x8BA4;&#x7B2C;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x540D;&#x7701;&#x7565;</li>
</ul>
</li>
</ul>
<pre><code class="lang-swift"><span class="hljs-func"><span class="hljs-keyword">func</span> <span class="hljs-title">sum1</span><span class="hljs-params">(num1 a: Int, num2 b: Int)</span> -&gt; <span class="hljs-title">Int</span> </span>{
    <span class="hljs-keyword">return</span> a + b
}

sum1(num1: <span class="hljs-number">10</span>, num2: <span class="hljs-number">20</span>)
</code></pre>

                    
                    </section>
                
                
                </div>
            </div>
        </div>

        
        <a href="./07-collection.html" class="navigation navigation-prev " aria-label="Previous page: 集合"><i class="fa fa-angle-left"></i></a>
        
        
        <a href="./09-closure.html" class="navigation navigation-next " aria-label="Next page: 闭包"><i class="fa fa-angle-right"></i></a>
        
    </div>
</div>

        
<script src="gitbook/app.js"></script>

<script>
require(["gitbook"], function(gitbook) {
    var config = {"fontSettings":{"theme":null,"family":"sans","size":2}};
    gitbook.start(config);
});
</script>

        
    </body>
    
</html>
